Monday 9 May 2011 15.13 EDT
First published on Monday 9 May 2011 15.13 EDT

Lady Neville-Jones has left her job as the Home Office minister for security and counter-terrorism amid repeated public gaffes and claims of private personality clashes.

Neville-Jones, a former high-flying Foreign Office career diplomat who at one point chaired the Cabinet's joint intelligence committee,said on Monday that she had told David Cameron at the start of the year that she wanted to "step down from the Home Office" around the time of the local elections.

But her 12 months as security minister was marked by blunders and clashes within Whitehall and in public. One appearance before the Commons home affairs select committee when she gave the impression of being ill-briefed on the government's replacement for control orders was regarded as particularly embarrassing. On another occasion she did not seem to know the name of a Home Office official advising her.

When the Conservatives were in opposition, she was given the role of national security adviser to Cameron but missed out on the job in government when the national security council was created.

In an exchange of letters with Cameron , Neville-Jones said that he could count on her support and she would "stand ready to take on assignments from you in the future".

Cameron paid tribute to her work in government and thanked her for her "wise advice over many years on national security issues".

The home secretary, Theresa May, announced that Lady Browning, who served in John Major's government as a junior agriculture minister, had been appointed as Home Office minister in the Lords to replace Neville-Jones.

It was not clear on Monday if Browning would take over her duties as counter-terrorism minister and it appears that May may have decided she does not need a separate security minister.

"I am delighted to welcome Baroness Browning to the Home Office and look forward to working with her to deliver our key priorities," said May.

"I would like to thank Baroness Neville-Jones for her hard work, both in opposition and in government, contributing to the rebalancing of security and liberty as well as participating in the work of the National Security Council."

Neville-Jones has been appointed by Cameron to be a special representative to business on cyber security.